4 police officers killed in Nigeria attacks

KANO, Nigeria 
Authorities say four police officers have been killed in two separate attacks in Nigeria.

One attack happened Thursday morning in Kano, a city of 9 million people in Nigeria's Muslim north. Police said in a statement that gunmen riding on motorcycles shot at a group of officers patrolling a street on foot.

The shooting comes after at least 185 people died in Kano last month in a coordinated assault by the radical Islamist sect known as Boko Haram. Boko Haram is waging an increasingly violent campaign against Nigeria's weak central government across its north.

Meanwhile, authorities say suspected Boko Haram members shot dead two police officers in Niger state and stole their rifles.